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[Qemu-devel] [PATCH] target-arm: Add guest cpu endianness determination
From: |
Pranavkumar Sawargaonkar |
Subject: |
[Qemu-devel] [PATCH] target-arm: Add guest cpu endianness determination for virtio in KVM ARM64 |
Date: |
Tue, 28 Oct 2014 12:08:01 +0530 |
This patch implements a fucntion pointer virtio_is_big_endian()
from "CPUClass" structure for arm64.
Function aarch64_cpu_virtio_endianness() is added to determine and
returns the guest cpu endianness to virtio.
This is required for running cross endian guests with virtio on ARM64.
Signed-off-by: Pranavkumar Sawargaonkar <address@hidden>
---
include/hw/virtio/virtio-access.h | 2 ++
target-arm/cpu64.c | 41 +++++++++++++++++++++++++++++++++++++++
2 files changed, 43 insertions(+)
diff --git a/include/hw/virtio/virtio-access.h
b/include/hw/virtio/virtio-access.h
index 46456fd..84fa701 100644
--- a/include/hw/virtio/virtio-access.h
+++ b/include/hw/virtio/virtio-access.h
@@ -23,6 +23,8 @@ static inline bool virtio_access_is_big_endian(VirtIODevice
*vdev)
return virtio_is_big_endian(vdev);
#elif defined(TARGET_WORDS_BIGENDIAN)
return true;
+#elif defined(TARGET_AARCH64)
+ return virtio_is_big_endian(vdev);
#else
return false;
#endif
diff --git a/target-arm/cpu64.c b/target-arm/cpu64.c
index c30f47e..789f886 100644
--- a/target-arm/cpu64.c
+++ b/target-arm/cpu64.c
@@ -192,6 +192,43 @@ static void aarch64_cpu_set_pc(CPUState *cs, vaddr value)
}
}
+#ifndef CONFIG_USER_ONLY
+
+#define KVM_REG_ARM64_SCTLR_EL1 3, 0, 1, 0, 0
+
+static bool aarch64_cpu_virtio_endianness(CPUState *cs)
+{
+ ARMCPU *cpu = ARM_CPU(cs);
+ CPUARMState *env = &cpu->env;
+ struct kvm_one_reg reg;
+ uint64_t sctlr;
+
+ cpu_synchronize_state(cs);
+
+ /* Check if we are running 32bit guest or not */
+ if (!is_a64(env))
+ return (env->pstate & CPSR_E) ? 1 : 0;
+
+ /* Ideally we do not need to call IOCTL again to read SCTLR_EL1 value.
+ * cpu_synchronize_state() should fill the env->cp15.c1_sys
+ * to get this value but this path is currently not implemented for arm64.
+ * Hence this is a temporary fix.
+ */
+
+ reg.id = ARM64_SYS_REG(KVM_REG_ARM64_SCTLR_EL1);
+ reg.addr = (uint64_t) &sctlr;
+ kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®);
+
+ if ((env->pstate & 0xf) == PSTATE_MODE_EL0t)
+ sctlr &= (1U <<24);
+ else
+ sctlr &= (1U <<25);
+
+ /* If BIG-ENDIAN return 1 */
+ return sctlr ? 1 : 0;
+}
+#endif
+
static void aarch64_cpu_class_init(ObjectClass *oc, void *data)
{
CPUClass *cc = CPU_CLASS(oc);
@@ -203,6 +240,10 @@ static void aarch64_cpu_class_init(ObjectClass *oc, void
*data)
cc->gdb_write_register = aarch64_cpu_gdb_write_register;
cc->gdb_num_core_regs = 34;
cc->gdb_core_xml_file = "aarch64-core.xml";
+#ifndef CONFIG_USER_ONLY
+ cc->virtio_is_big_endian = aarch64_cpu_virtio_endianness;
+#endif
+
}
static void aarch64_cpu_register(const ARMCPUInfo *info)
--
1.9.1
- [Qemu-devel] [PATCH] target-arm: Add guest cpu endianness determination for virtio in KVM ARM64,
Pranavkumar Sawargaonkar <=